Environmental systems and societies

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Shaaban
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Joined: Mon Jun 24, 2019 5:25 am
Occupation: Student

Environmental systems and societies

Post by Shaaban »

Hello! I am doing an experiment about the effect of acid rain on aquatic plants in which I am using sulfuric acid to vary the Ph and a plant called Limnophila sessiliflora. I will be collecting my data by measuring the volume of oxygen produced by the plant a few hours later. My question is, will the aquatic plant survive or in other way photosynthesize effectively in tap water during the experiment or is it more ideal to make my own water samples by adding essential nutrients to distilled water?
DrSullivan
Former Expert
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Joined: Mon May 06, 2019 11:46 am
Occupation: Other Adult

Re: Environmental systems and societies

Post by DrSullivan »

If it is an aquarium plant, I believe tap water should be fine as long as you de-chlorinate it. This can be done with tablets from the pet store or by leaving the tap water uncovered at room temperature overnight.

You can look at more specific lighting, pH, and CO2 requirements at this link.

http://dedicatedaquariums.com/limnophila-sessiliflora/
Shaaban
Posts: 5
Joined: Mon Jun 24, 2019 5:25 am
Occupation: Student

Re: Environmental systems and societies

Post by Shaaban »

Hi! I am doing an experiment to explore the effect of acid rain on aquatic plants. In this experiment, I am looking at the number of bubbles released from the cut end. I have my data but I am confused as I want to find the correlation between pH and photosynthesis rate. I do not know which regression function fits my scatter plot best (linear, exponential, etc) and what type of statistical test would be appropriate to test the significance of the correlation (T-test, chi-square person's ).
pharrast
Former Expert
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Joined: Wed Jul 31, 2019 4:19 pm
Occupation: Student

Re: Environmental systems and societies

Post by pharrast »

This is a really difficult question, so don't feel like you should have known.
I am not good enough at math to explain all of regression models and significance, but I can at least send this along: https://blog.minitab.com/blog/adventure ... regression
There is also this: https://mycurvefit.com/.
If you're using excel, I think you have to use the LINEST function, which I am not familiar with. If you know how to use R or Matlab or something, great! I would guess it will be pseudo-bell-shaped.
IF LINEAR, you will use r-squared and what underlies the r^2: Pearson's r, a measure of covariance (https://sciencing.com/calculate-pearson ... 70547.html). The general rule is r<0.3 is weak correlation, r<0.5 is medium, and r>0.5 is a strong correlation.
When regression models are non-linear, that goes out the window and you have a lot of complicated stuff to figure out using the tools above.
Sorry I can't be more helpful, maybe trying to get a math expert in would be a good idea, though I just went down the stats rabbit hole and came out with the impression that doing what you're hoping on a non-linear regression might involve custom testing.
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